7 QC TOOLS & TECHNIQUES

7 Quality control tools

7 QC TOOLS — Quality pros have many names for these seven basic tools of quality, first emphasized by Kaoru Ishikawa, a professor of engineering at Tokyo University and the father of “quality circles.” Start your quality journey by mastering these tools, and you’ll have a name for them too: indispensable.

Basic Seven Tools of Quality Control

1. Check Sheet
2. Stratification
3. Pareto Chart
4. Cause and Effect Diagram
5. Histogram
6. Scatter Diagram
7. Graph and Control Chart
8. Check sheet: A structured, prepared form for collecting and analyzing data; a generic tool that can be adapted for a wide variety of purposes.
9. Stratification: A technique that separates data gathered from a variety of sources so that patterns can be seen (some lists replace stratification with a flowchart or run chart).
10. Pareto chart: A bar graph that shows which factors are more significant.
11. Cause-and-effect diagram (also called Ishikawa or fishbone diagrams): Identifies many possible causes for an effect or problem and sorts ideas into useful categories.
12. Histogram: The most commonly used graph for showing frequency distributions or how each different value in a set of data often occurs.
13. Scatter diagram: Graphs pairs of numerical data, one variable on each axis, to look for a relationship.
14. Control chart: Graph used to study how a process changes over time. Comparing current data to historical control limits leads to conclusions about whether the process variation is consistent (in control) or is unpredictable (out of control, affected by special causes of variation). Read more